He even has a nice nickname: geographical animal. And it got that fame because it gets under the skin, drawing lines that look like nonexistent maps. Have you ever been a victim? Well, the geographical animal is frequent in several beaches of our country. The parasite, officially named Ancylostoma, really likes to infect cats and dogs to develop in their intestines.
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In 1908 the English mathematician Godfrey H. Hardy (1877 - 1947) and the German physician Wilhem Weinberg concluded that if no evolutionary factor acted on a population that met certain conditions, the frequencies of their alleles would remain unchanged across generations. This principle became known as the Hardy-Weinberg law or theorem of gene equilibrium.
The importance of certain chemical elements and mineral substances for human metabolism is becoming increasingly evident. The table below summarizes the main chemical elements needed by the human body. Among them, macronutrients are the ones we use in large quantities, while micronutrients are used in small quantities.
Blood entering the glomerulus is under high pressure, about 75 mmHg. This pressure forces the passage of water and small molecules (amino acids, glucose, salts, urea, etc.) into the Bowman capsule. Cells (white and red blood cells) and large molecules (proteins) do not cross the glomerular wall.
Ulcers are tears in the surface of an inflamed or non-inflamed organ or tissue. Usually appearing on the stomach wall, is the most common digestive tract disease. It develops in the form of an off-white crater with a rough reddish rim. They can be shallow or deep, the size of a coin.
The fluid balance in the body is closely linked to the presence and amount of sodium ion in the blood. When we eat salty foods, our blood sodium increases, which causes increased blood tonicity. Nervous centers in the hypothalamus, the thirst centers, detect this increase in tone and produce the sensation of thirst.
Nerves attached to the brain are called cranial nerves, while nerves attached to the spinal cord are called spinal or spinal nerves. Mammals, birds and reptiles have twelve pairs of cranial nerves, which are responsible for the innervation of the sense organs, muscles and glands of the head, as well as some internal organs.
Gonadotropins FSH (follicle stimulating hormone) and LH (luteinizing hormone) are produced by the anterior portion of the pituitary and regulate the activity of the ovaries and testes. These organs, in turn, will produce hormones that will act on the emergence of secondary sexual characters and the process of human reproduction.
The gills (popularly known as gills) of bony fish are lateral projections of the pharynx, located in a gill chamber. To find them, the operculum must be lifted by a protective bony cover located laterally near the head. Each gill consists of delicate gill filaments.
Excretion is the mechanism by which excretory structures or organs remove excreta, true cellular “wastes,” such as ammonia (NH 3), urea, CO 2, salts, and H 2 O. In this way, the body will maintain the balance of the internal environment, that is, homeostasis. Excretory mechanisms in animals In less complex animals that live in the aquatic environment, the elimination of cellular waste resulting from metabolism is generally by simple diffusion on the body surface.
The nasal passages (or nasal cavities) and the mouth are the air inlets that travel to our respiratory system. The air that enters the nasal passages is filtered, moistened and heated before going to the trachea. Eyelashes lining the epithelium of the nasal cavities trap dirt particles and microorganisms that exist in the air.
Many animals have colored substances in their blood or hemolymph called respiratory pigments. These substances are able to combine with oxygen gas, significantly increasing the body's ability to transport this gas. The main respiratory pigments present in animals are hemoglobin and hemocyanin.
The olfactory epithelium located in the nasal cavities of most vertebrates, for example, is endowed with cells specialized in the capture of odors of various types, even at very small concentrations. There are two types of materials in the environment: those that give off particles (such as roses, perfumes, warm bread being baked in the oven) and others that do not (such as steel and glass).
In humans and other mammals, pulmonary ventilation depends on the intercostal muscles (located between the ribs) and the diaphragm. The air entering the lungs, the inspiration, is due to the contraction of the diaphragm muscles and intercostal muscles. The diaphragm lowers and the ribs rise, which increases the volume of the rib cage, forcing air into the lungs.
Fish Hearing Fish ears are embedded in the bones of the skull, one on each side of the head. They consist of one saccule, one utricle and three semicircular canals. Because of their location they are called inner ears. Sound waves transmitted by water reach the fish's body, spreading through the skull bones to the saccule.
Both the sense of balance and that of hearing depend on the action of mechanoreceptors, hair cells that detect the movement of solid or liquid particles. Most animals maintain a definite orientation to Earth's gravity; when taken from their typical position, they try to return to it.
Prior to the scientific attempts related to the origin of life, the idea of special creation, according to which life is the result of the conscious action of a Creator, was already widespread. This stream of thought, which has come to be called creationist, is based on faith and the biblical texts - especially the book of Genesis - that relate the idea of the origin of life from the religious point of view.
Mammals need a nutritious and abundant diet because the metabolic costs of maintaining temperature are very high, but according to the diet, the digestive tract may have specific adaptations. In carnivores the digestive tract is simple because the proteins, lipids and minerals found in meat do not require specialized digestion.
The vast majority of animals have nerve and muscle cells. In all of them, the mechanism of operation of these cells is exactly the same. The internal coordination of the organism and its relationship with the environment are functions performed by the nervous system. The sensory system is responsible for receiving messages from the environment.
In the contraction of skeletal muscle fibers, sarcomere shortening occurs: actin filaments “glide” over those of myosin, thanks to certain binding points that form between these two filaments, leading to the formation of actomyosin. For this slip to happen, a large amount of two important elements participate: Ca ++ and ATP ions.
Let us now briefly describe two important diseases related to the action of “defective” genes. Phenylketonuria Phenylketonuria (PKU) is a genetic disease due to the action of a recessive gene that manifests in homozygosis, affecting approximately 1 in 12,000 newborns in Brazil.